8 mm video tape cassettes have been successfully developed in the past few years. Before the success, conventional large tape cassettes like VHS, BETA, VHS-C, etc., have been developed for a long time, and the tape rewinding technique for large tape is rather satisfactory, no matter whether it is a single tape rewinding machine or a combination of video cassette recorder and tape rewinding apparatus. However, because 8 mm miniature video tape cassettes do not have rollers to avoid rubbing between tape and cassette case while tape transfer, the tape rewinding mechanism design must be more elaborated to eliminate such rubbing. Consequently, it needs more technique than the conventional large video tape, particularly for a tape rewinding apparatus with a bi-directional automatic rewinding feature. Up to the present, some video cassette recorders that have bi-directional rewinding devices for 8 mm video tape are rather complicated and most of them employ two motors as power sources.
In addition, some manufacturers make 8 mm tape rewinding machines by separating the rewinding apparatus from video cassette recorders and controlling the operation sequence of two motors by complex integrated circuits to acquire the effect of automatic bi-directional tape rewinding. Besides, a design that employs complicated mechanical gear transmission control system to substitute for the foregoing sequence control of integrated circuits has not succeeded due to its high complexity.
8 mm video tape has gradually become popular. There is an increasing demand for a separate automatic bi-directional tape rewinding apparatus.